Claude 3 Sonnet vs Kimi K2
Anthropic Claude 3 Sonnet | Moonshot AI Kimi K2 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Mar 4 2024 | Jul 11 2025 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 1T |
Context window | — | 128k |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | — | 10% |
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | — | 65.8% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 40.4% | 75.1%Best |
| Timeline | ||
| Release gap | Claude 3 Sonnet shipped 494 days before Kimi K2 | |
Which is better: Claude 3 Sonnet or Kimi K2?
Kimi K2 leads Claude 3 Sonnet on 1 of the 1 benchmark they both report (GPQA Diamond). Claude 3 Sonnet shipped 494 days before Kimi K2, so benchmark comparisons should account for the intervening progress.
Claude 3 Sonnet is proprietary, while Kimi K2 is open weight.
On GPQA Diamond, Kimi K2 leads at 75.1% vs Claude 3 Sonnet at 40.4%.
Frequently asked questions
Claude 3 Sonnet was released by Anthropic on Mar 4 2024.
Kimi K2 was released by Moonshot AI on Jul 11 2025.
Kimi K2 leads on GPQA Diamond — Claude 3 Sonnet 40.4% vs Kimi K2 75.1%.
Claude 3 Sonnet is a proprietary model released by Anthropic. Kimi K2 is an open weight model released by Moonshot AI.
Other comparisons
Claude 3 Sonnet vs GPT-5.6 SolKimi K2 vs GPT-5.6 SolClaude 3 Sonnet vs Gemini OmniKimi K2 vs Gemini OmniClaude 3 Sonnet vs Muse Spark 1.1Kimi K2 vs Muse Spark 1.1Claude 3 Sonnet vs Grok 4.5Kimi K2 vs Grok 4.5Claude 3 Sonnet vs DeepSeek-V4-ProKimi K2 vs DeepSeek-V4-ProClaude 3 Sonnet vs Mistral Medium 3.5Kimi K2 vs Mistral Medium 3.5